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authorYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 12:17:53 -0700
committerYunhong Jiang <yunhong.jiang@intel.com>2015-08-04 15:44:42 -0700
commit9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch)
tree1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/devicetree/bindings/rtc/isil,isl12057.txt
parent98260f3884f4a202f9ca5eabed40b1354c489b29 (diff)
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
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+Intersil ISL12057 I2C RTC/Alarm chip
+
+ISL12057 is a trivial I2C device (it has simple device tree bindings,
+consisting of a compatible field, an address and possibly an interrupt
+line).
+
+Nonetheless, it also supports an option boolean property
+("isil,irq2-can-wakeup-machine") to handle the specific use-case found
+on at least three in-tree users of the chip (NETGEAR ReadyNAS 102, 104
+and 2120 ARM-based NAS); On those devices, the IRQ#2 pin of the chip
+(associated with the alarm supported by the driver) is not connected
+to the SoC but to a PMIC. It allows the device to be powered up when
+RTC alarm rings. In order to mark the device has a wakeup source and
+get access to the 'wakealarm' sysfs entry, this specific property can
+be set when the IRQ#2 pin of the chip is not connected to the SoC but
+can wake up the device.
+
+Required properties supported by the device:
+
+ - "compatible": must be "isil,isl12057"
+ - "reg": I2C bus address of the device
+
+Optional properties:
+
+ - "isil,irq2-can-wakeup-machine": mark the chip as a wakeup source,
+ independently of the availability of an IRQ line connected to the
+ SoC.
+
+ - "interrupt-parent", "interrupts": for passing the interrupt line
+ of the SoC connected to IRQ#2 of the RTC chip.
+
+
+Example isl12057 node without IRQ#2 pin connected (no alarm support):
+
+ isl12057: isl12057@68 {
+ compatible = "isil,isl12057";
+ reg = <0x68>;
+ };
+
+
+Example isl12057 node with IRQ#2 pin connected to main SoC via MPP6 (note
+that the pinctrl-related properties below are given for completeness and
+may not be required or may be different depending on your system or
+SoC, and the main function of the MPP used as IRQ line, i.e.
+"interrupt-parent" and "interrupts" are usually sufficient):
+
+ pinctrl {
+ ...
+
+ rtc_alarm_pin: rtc_alarm_pin {
+ marvell,pins = "mpp6";
+ marvell,function = "gpio";
+ };
+
+ ...
+
+ };
+
+ ...
+
+ isl12057: isl12057@68 {
+ compatible = "isil,isl12057";
+ reg = <0x68>;
+ pinctrl-0 = <&rtc_alarm_pin>;
+ pinctrl-names = "default";
+ interrupt-parent = <&gpio0>;
+ interrupts = <6 IRQ_TYPE_EDGE_FALLING>;
+ };
+
+
+Example isl12057 node without IRQ#2 pin connected to the SoC but to a
+PMIC, allowing the device to be started based on configured alarm:
+
+ isl12057: isl12057@68 {
+ compatible = "isil,isl12057";
+ reg = <0x68>;
+ isil,irq2-can-wakeup-machine;
+ };